Compound engine



(No Model.) Y

G. F. ROUNDS.

COMPOUND ENGINE. No. 455,670. PatentedJuly 7, 1891.

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UNITED STATES PATENT OFFICE.

GEORGE F. ROUNDS, OF BENTON HARBOR, MICHIGAN.

COMPOUND ENGINE.

SPECIFICATION forming part of Letters Patent No. 455,670, dated July 7, 1891. Application led April 15, 1891. Serial No. 389,007. (No model.)

To aZZ whom it may concern:

Be it known that I, GEORGE F. RoUNDs, ofl

- to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawings, which form part of this specication.

My invention relates to an improvement in compound engines; and it consists in a casting, Which is attached to the exhaust-port of the high-pressure cylinder, and an oscillating relief-valve that is placed therein, and which controls the escape of the exhaust-steam,and is operated by the eccentric on the main shaft through an eccentric-rod combined with a check-valve and a receiver for the exhauststeam, as will be more fully described hereinafter.

The object of my invention is to relieve the high-pressure cylinder of a compound engine of back-pressure by using c receiver.

Figure l is a vertical section of an apparatus which embodies my invention. Fig. 2 is a vertical section taken through the apparatus at right angles to Fig. l.

A represents the high-pressure cylinder, and attached to its exhaust-port is the cylindrical casting B, to one side of which is secured the pipe X, which conveys the steam to the condenser. Passing through one end of this casting B is the shaft I, which has its inner end journaled in a suitable bearing in the end of the casting B, and which shaft has secured to its outer end an arrn or crank G, to which the eccentric-rod F is fastened. This rod F is operated by an eccentric on the main shaft and serves to impart to the shaft I an oscillating movement.

Projecting from a sleeve, which is secured loose on the shaft I inside of the casting, is the relief-valve C, which controls the port I-I. To the valve C is given a back-andforth or oscillating movement through the eccentric-rod F, so as to alternately open and close the port H at regular predetermined intervals. Through the casting Bis also made an opening, in which the spring-actuated check-valve E is placed, and connected to the casting B, by a suitable casting D, is the receiver O for the exhaust-steam. At the time of the exhaust of the cylinder A the relief-valve C closes the port H, and then the exhaust-steam passes from the casting .B past the check-valveE to the receiver O. As soon as the pressure in the receiveris nearly equal 6o to that in the cylinder A, the check-valve E closes either from its own Weight or the action of the spring, and then the relief-valve C is opened by the action of the eccentric through the rod F and the relieved steam passes through the pipe X to the condenser. The time between the exhaust and the relief is controlled by the lap of the relief-valve C.

My invention is applicable especially to compound engines having a high and a lor 7o pressure cylinder. The low-pressure cylinder, as usual, is preferably about twice the size of the high-pressure cylinder A and has. its steam-chest connected in any suitable manner to the receiver O.

In operation the high-pressure cylinder A exhausts into the receiver O, and as soon as the pressure in the receiver-is equal to the pressure in the exhaust side of the high-pressure cylinder the check-valve E closes and the 8o relief-valve C opens, which prevents any backpressure from the receiver O to the highpressure cylinder. The steam from the cas*- ing B passes into the pipe X, and from thence to the condenser, thus making the high-press- 8 5 ure cylinder a low-pressure cylinder for a portion of its exhaust, which, as will readily be understood, greatly increases the efficiency of the said cylinder.

By means of the construction here shown 9o the high-pressure cylinder of the compound engine is relieved of back-pressure, a-nd the action of the engine is greatly improved in every way.

The parts which constitute my invention are few and simple and are not liable to get out of repair while in operation.

Having thus described my invention, I claiiny l. The cylinderand the receiver, combined roo In a compound engine, a high-pressure cylinder, combined with a low-pressure cylinder hy means of the exhaust of the former and zi check and relief valve between the t-Wo, substantially as described.

In testimony whereof I afx my signature in presence of two witnesses.

GEORGE F. ROUNDS.

.Vitnesses:

M. V. BUCHANAN, A. H. FLANEGAN. 

